Crystallization of inorganic solids at self-organized organic or biomacromolecular surfaces is an important process in biomineralization and crystal engineering. Thereinto, Langmuir monolayers are often used as simple models of biomineralization; they can guide the growth of oriented crystals of specific structure, size, and morphology. In this paper, the growth of the CaF₂ crystals induced in situ by Langmuir monolayers as the template was investigated by means of SEM, XPS and XRD. The results of XRD show that CaF₂ grows only along the (111) face under benhenic acid (BA) monolayer, which indicates (111) direction is preferable orientation for the growth of CaF₂ crystals; SEM shows that the morphology of the CaF₂ crystals induced by BA monolayer is relatively regular and simplex, but in the bulk solution, it's irregular and easy to form large size grains. Those may be reasonably explained by lattice matching between the benhenic acid headgroups in the monolayer and the CaF₂ crystals lattice which were fabricated under monolayer. ( From : No.1, 2006 Journal of Inorganic Materials )